Our current research interests include but are not limited to the biological mechanism of alveolar bone remodeling, craniofacial bone regeneration, translational research, and clinical studies related to orthodontics.
Exploring the Biological Mechanism during Alveolar Bone Remodeling
Alveolar bone remodeling is a dynamic process crucial for maintaining dental and periodontal health, which involves the balance of activity between osteoclasts and osteoblasts. It is regulated by various signaling pathways, including those mediated by cytokines and mechanical stress. We carried out tensional stimuli in vitro for periodontal ligament cells and then added the inhibitor of the RhoA/Rho-associated kinase pathway to reduce the Yes-associated protein (YAP) expression and tension-induced cell differentiation. Besides, we added mechanical compressive stress in vitro for cementoblasts and osteoblasts and then found the effect of transforming growth factor-beta 1 (TGF-𝛽1) on osteoprotegerin/receptor activator of nuclear factor kappa-B ligand (OPG/RANKL) expression has changed. In addition to cell experiments, we also carried out orthodontic tooth movement on rats and mice, andcompared the expression of YAP, sclerostin, and other signals in the tension sides and compression sides.
Accelerating the Craniofacial Bone Tissue Regeneration Process
Craniofacial bone defects can be caused by genetic diseases, trauma, or congenital abnormalities, and some treatments involve the process of bone regeneration with additional support, such as scaffolds and stem cells. The process encompasses dynamic interdisciplinary fields of engineering, biology, and materials, including an understanding of biomaterial structure, signaling pathways, cytokines, and the intracellular and extracellular responses to orchestrate cell behavior, proliferation, and differentiation. We have tried novel biomaterials for stimulating bone regeneration in rabbits, followed by microCT and staining analyses. We also tested biomolecules for inducing the osteogenic differentiation of mesenchymal stromal cells for potential application in promoting craniofacial bone regeneration. These strategies aim to create a conducive environment that mimics the natural bone tissue regeneration procedures, ultimately leading to faster recovery and improved outcomes in vitro, in vivo, and in the clinic.
Translational Research: From Bench Side to Bedside
We hope the scientific discoveries made in our laboratory will be transformed into practical treatments and therapies for our patients, which involve multiple stages from basic research to understanding the mechanisms to identify the potential therapeutic targets. The process also requires collaborations across disciplines including biologists, chemists, clinicians, and other experts, to bridge the gap between laboratory research and patient care. Our examples include injecting hyaluronic acid combined with glucosamine oral administration to treat patients with temporomandibular disorders of osteoarthritis through a double-blinded randomized control trial and then detecting the inflammatory and other related cytokines in the joint synovial fluid to elucidate the biomolecular regulation mechanism. Besides, we studied the West African population who showed an extreme form of mandibular osteonecrosis and osteomyelitis by extracting the DNA from their mandibular fragments for whole-genome sequencing. We continue working on some translation studies that combined both clinical data and basic science discoveries, which will directly benefit the patients with their treatment.
Clinical Studies related to Orthodontics and Dentistry
As clinician scientists, we have also been working on clinical trials such as the experimental (RCT and non-RCT) and observational (cohort, case control, and cross-sectional) studies. We have been conducting a series of research regarding facial esthetics, including the importance of sagittal and oblique smiling profiles, the harmony of maxillary arch width, with interparopia width and smile width, as well as the importance of maxillary incisor position. Besides, we have been carrying out some systematic reviews and meta-analyses regarding the controversial topics in orthodontics and dentistry to provide more evidence for clinicians to make better decisions for their patients. For examples, we tried to figure out the clinical importance of self-ligating brackets with the conventional bracekts, and have found that self-ligating brackets do not show clinical superiority compared to conventional brackets in expanding transversal dimensions, space closure, orthodontic efficiency, promoting oral health, or discomfort relief for patients under orthodontic treatment.
Part of our publications:
[1] Yang X, Ye AY, Katebi N, Volloch V, Khullar SM, Patel V, Olsen BR. Mycobacterial and Plasmodium ovale‐associated destruction of the jaw bones. Oral Diseases. 2022;28(2):452-68. [2] Yang X, Paulo JA, Hu K, Gygi S, Olsen BR, Yalak G. Novel insights into roles of the FGFR2 secreted kinase in extracellular matrix, cell and developmental biology. In JOURNAL OF BONE AND MINERAL RESEARCH 2022 Feb 1 (Vol. 37, pp. 187-187). 111 RIVER ST, HOBOKEN 07030-5774, NJ USA: WILEY. [3] Yang X, Li L, Xiao L, Zhang D. Recycle the dental fairy’s package: overview of dental pulp stem cells. Stem Cell Research & Therapy. 2018;9:1-8. [4] Yang X, Han X, Shu R, Jiang F, Xu L, Xue C, Chen T, Bai D. Effect of sclerostin removal in vivo on experimental periodontitis in mice. Journal of oral science. 2016;58(2):271-6. [5] Yang X, Wang Y, Han X, Shu R, Chen T, Zeng H, Xu X, Huang L, Ren A, Song J, Cao L. Effects of TGF-β1 on OPG/RANKL expression of cementoblasts and osteoblasts are similar without stress but different with mechanical compressive stress. The Scientific World Journal. 2015 Oct;2015. [6] Yang X, Justus R, Li B, Xue C, Lee IT, Guo Y, Bai D, Han X, Xu H. Customized planning of the visible maxillary arch width in harmony with interparopia width and smile width for female facial aesthetics. Orthodontics & Craniofacial Research. 2024; 27(1):139-150 [7] Yang, X., Yi, Y., Yang, S., Xue, C., Wang, Y., Chen, M., Han, X., Bai, D. Role of sagittal and oblique smiling profiles in evaluating facial esthetics. Journal of Craniofacial Surgery, 2015;26(2), 532-536. [8] Yang X, Li C, Bai D, Su N, Chen T, Xu Y, Han X. “Treatment effectiveness of Fränkel function regulator on the Class III malocclusion: a systematic review and meta-analysis.” Am J Orthod Dentofacial Orthop. 2014;146(2):143-154. [9] Cui L, Zhang J, Zou J, Yang X, Guo H, Tian H, Zhang P, Wang Y, Zhang N, Zhuang X, Li Z. Electroactive composite scaffold with locally expressed osteoinductive factor for synergistic bone repair upon electrical stimulation. Biomaterials. 2020 Feb 1;230:119617. [10] Wang L, Heckmann BL, Yang X, Long H. Osteoblast autophagy in glucocorticoid‐induced osteoporosis. Journal of cellular physiology. 2019; 234(4):3207-15. [11] Yang S, Guo Y, Yang X, Zhang F, Wang J, Qiu J, Li J. “Effect of mesiodistal angulation of the maxillary central incisors on esthetic perceptions of the smile in the frontal view.” Am J Orthod Dentofacial Orthop. 2015;148(3):396-404. [12] Li Z, Jiang Z, Zhao L, Yang X, Zhang J, Song X, Liu B, Ding J. PEGylated stereocomplex polylactide coating of stent for upregulated biocompatibility and drug storage. Materials Science and Engineering: C. 2017;81:443-51. [13] Cen X, Liu Y, Wang S, Yang X, Shi Z, Liang X. Glucosamine oral administration as an adjunct to hyaluronic acid injection in treating temporomandibular joint osteoarthritis. Oral Diseases. 2018;24(3):404-11. [14] Shu R, Bai D, Sheu T, He Y, Yang X, Xue C, He Y, Zhao M, Han X. Sclerostin promotes bone remodeling in the process of tooth movement. PLoS One. 2017;12(1):e0167312. [15] Chen T, Liu Z, Sun W, Li J, Liang Y, Yang X, Xu Y, Yu M, Tian W, Chen G, Bai D. Inhibition of Ape1 redox activity promotes odonto/osteogenic differentiation of dental papilla cells. Scientific Reports. 2015;5(1):17483. [16] He Y, Xu H, Xiang Z, Yu H, Xu L, Guo Y, Tian Y, Shu R, Yang X, Xue C, Zhao M. YAP regulates periodontal ligament cell differentiation into myofibroblast interacted with RhoA/ROCK pathway. Journal of Cellular Physiology. 2019;234(4):5086-96.